Lecture Notes on 12 Aug 2013

import math

class Point (object):
  # initializer
  def __init__ (self, x = 0, y = 0):
    self.x = x
    self.y = y

  # get distance
  def dist (self, p):
    return math.hypot (self.x - p.x, self.y - p.y)

  # string representation
  def __str__ (self):
    return '(' + str(self.x) + ', ' + str(self.y) + ')'

class Circle (object):
  # initializer
  def __init__ (self, x = 0, y = 0, radius = 1):
    self.center = Point (x, y)
    self.radius = radius

  # compute area
  def area (self):
    return math.pi * self.radius * self.radius

  # compute circumference
  def circumference (self):
    return 2.0 * math.pi * self.radius

  # string representation
  def __str__ (self):
    return 'Center = ' + str(self.center) + '  Radius = ' + str(self.radius)

def main():
  # Create Point objects
  p = Point (1, 2)
  print (p)
  q = Point (3, 4)
  print (q)
  p.x = 6
  p.y = 7
  print (p)
  print (p.dist(q))

  circleC = Circle (1, 1, 2)
  print (circleC)
  print (circleC.area())

main()